Not Applicable
Not Applicable
This is a Continuation in Part of U.S. patent application Ser. No. 09/369,350 filed Aug. 6, 1999 now U.S. Pat. No. 6,109,673. The art in which the present invention resides thus is likewise broadly defined by tamper-evident seals that are at least in part reusable.
The present invention extends and amplifies the art disclosed in the parent application by offering improved adjustability, reduced cost of manufacture, and easier application to external devices. As before, in the parent application, the present invention has two, reusable catches, but now adds an engaging-element whose engagement-length is adjustable, yet which has, with respect to each catch, a unique, weakest point for that catch, so located as to prevent reuse of the engaging-element once it has been broken.
Security devices having dual catches, and further having engaging-elements whose engagement-length is individually adjustable at each catch are well known. A bilaterally symmetric device having two catches and two, adjustable-length, linear ratchets is taught by U.S. Pat. No. 4,910,831 to Bingold (1990). Bingold""s device, however, does not provide weak points at which its respective linear ratchets sever preferentially from the overall device. The severing from Bingold""s device of his linear ratchets would, in fact, destroy the utility of Bingold""s device, because it is intended to function as a handcuff.
The present invention provides an engaging-element, referred to in shorthand-manner as the xe2x80x9csealxe2x80x9d, comprising a long mid-section and two linear ratchets, one each abutting the opposite ends of the mid-section, each linear ratchet in itself further comprising a plurality of abruptly shouldered sub-elements. The long mid-section and each of the two, linear ratchets further respectively comprise a pair of parallel side rails. The parallel side rails of each linear ratchet help to prevent the linear ratchet from breaking at any one of the several junctions of its successive, abruptly-shouldered sub-elements when stressed.
Taken together, the long mid-section and the two linear ratchets form the top portion of the engaging-element. In the present invention, this top portion has two, least cross-sectional areas, these being coincident with the junctions of the linear ratchets with the long mid-section. A tugging force applied to the seal""s top portion at either end, such as a force tending to pull the catches of the present invention apart after the seal has been brought into lockable engagement with both catches, thus will sever one or the other of the linear ratchets in its entirety from the remainder of the seal, rather than severing one or the other of the linear ratchets internally, at one of the junctions between two of its adjacent, abruptly-shouldered sub-elements.
The greatest cross-section of the seal""s mid-section orthogonal to its length is geometrically substantially similar to (it is H-shaped in the embodiment herein illustrated) to the greatest, parallel cross-section of either of the linear ratchets, and is furthermore not greater than this cross-section in either area or longest dimension. These cross-sectional relationships allow the mid-section to pass easily on its own through either catch.
Attached to the mid-section is an identification element which, as in the parent application, may be torn off by a twisting force applied substantially orthogonally to the force needed to sever either of the linear ratchets from the engaging-element.
The catches, in order to be reusable, are injection molded out of a rugged thermoplastic, such as nylon or polycarbonate. The engaging-element is injection molded out of a much weaker, more elastic material, polypropylene for example.
The engaging-element illustrated herein is bilaterally symmetric, although one of its linear ratchets might be made longer than the other, should such an asymmetry suit a particular purpose.
Each catch of the present invention bears an asymmetric, clasp-like feature that allows easy attachment of the catch to a variety of external devices. The present invention furthermore displays, if one may so speak, a generally square aesthetic, as opposed to the organic, rounded aesthetic of the parent invention. This squaring-off of elements can help to reduce mold-making costs, inasmuch as parting lines can now be positioned with one greater degree of freedom.
With the foregoing in mind, it is an important object of the present invention to offer a tamper-evident seal that is easily and bilaterally adjustable.
It is yet another object of the present invention to permit this adjustability and yet to prohibit the reuse of the engaging-element.
It is yet another object of the present invention to provide a tamper-evident seal having multiply-reusable catches that may be easily attached to a variety of external devices.
It is still a further object of the present invention to reduce mold-making costs.
These and yet further objects and advantages of the present invention will become apparent from a consideration of the following, detailed specification, drawings, and appended claims.